This specification relates to using acoustic waves in cleaning and sensing applications, and more particularly, to using acoustic waves for cleaning and sensing in data storage devices and systems.
Surface adhesion can attach fine particles to a surface. Such adhered particles may cause adverse effects and hence can be undesirable in certain applications. For example, adhered particles on a semiconductor wafer can degrade the performance and liability of integrated circuits fabricated on the wafer. Such surface-adhered particles can also cause problems in manufacturing masks for photolithography.
Acoustic waves have been used to remove surface-adhered particles from surfaces. In one implementation, a semiconductor wafer is immersed in a liquid and ultrasonic waves are generated to detach the adhered particles from the wafer surface into the liquid. In another implementation, laser pulses are used to impact on a surface to produce surface acoustic waves (xe2x80x9cSAWsxe2x80x9d) on the surface. The generated surface acoustic waves produce a force on an attached particle that is greater than the adhesive surface bonding force, to detach the particle from the surface.
The techniques and devices of the present disclosure use acoustic waves to reduce the amount of surface-adhered particles on a head that couples energy to a medium surface. Such particles may adversely affect the operations of a device using such a head by, among other things, distorting signals that are coupled between the head and the medium surface.
A device according to one embodiment includes a head having an interfacing surface that faces a medium surface and an acoustic transducer engaged to the head. The head is designed to couple energy from the interfacing surface to the medium surface. The head can be configured to couple any one type or a combination of different types of energy to the medium surface. For example, the head may be an optical head that couples optical waves. The head may also be a magnetic head that interacts with the medium surface through magnetic coupling. Furthermore, the head may be a hybrid head to interact with the medium surface by both optical and magnetic signals.
The acoustic transducer generates an acoustic wave that propagates to at least a portion of the interfacing surface to reduce particles adhered thereon. The acoustic wave may be a surface wave or a bulk wave. The acoustic transducer for generating surface acoustic waves may include a layer of piezo-electric material and a layer of transducer electrodes formed on the piezo layer. The transducer electrodes are electrically excited to cause the piezo layer to generate the acoustic waves.
These and other aspects and associated advantages will become more apparent in light of the detailed description, the accompanying drawings, and the appended claims.